Perpendicular magnetic recording media are being increasingly used for various applications in consumer electronics and in particular hard disks. In contrast to traditional longitudinal magnetic recording media, where the magnetic orientation of individual magnetic domains is generally parallel to the surface of the medium, perpendicular magnetic recording media have magnetic orientation of individual magnetic domains perpendicular to the surface of the medium. This allows for a much higher storage density than have been achieved in longitudinal magnetic recording media.
To meet the industry requirement for ever-increasing amounts of data storage in a given amount of hard disk area (also known as ‘areal density’), continuous improvement in the arrangement of perpendicular magnetic recording media is needed. One technique in which to achieve higher areal density is to reduce the grain size of the magnetic recording media. However, applying this technique to perpendicular recording media results in a poor switching field distribution dHc/Hc and poor crystal orientation Δθ50. This in turn results in higher media noise, which cancels any improvement in signal-to-noise ratio (SNR) obtained by using smaller grains.